Improving alginate printability for biofabrication: establishment of a universal and homogeneous pre-crosslinking technique

• Published in: Biofabrication 2020-10, Vol.12 (4), p.45004-045004
• Main Authors: Hazur, Jonas, Detsch, Rainer, Karakaya, Emine, Kaschta, Joachim, Teßmar, Jörg, Schneidereit, Dominik, Friedrich, Oliver, Schubert, Dirk W, Boccaccini, Aldo R
• Format: Article
• Language: English
• Subjects: alginate; bioink; bioprinting; pre-crosslinking; printability; rheology; shape fidelity
• ISSN: 1758-5082; 1758-5090
• DOI: 10.1088/1758-5090/ab98e5

Many different biofabrication approaches as well as a variety of bioinks have been developed by researchers working in the field of tissue engineering. A main challenge for bioinks often remains the difficulty to achieve shape fidelity after printing. In order to overcome this issue, a homogeneous pre-crosslinking technique, which is universally applicable to all alginate-based materials, was developed. In this study, the Young's Modulus after post-crosslinking of selected hydrogels, as well as the chemical characterization of alginate in terms of M/G ratio and molecular weight, were determined. With our technique it was possible to markedly enhance the printability of a 2% (w/v) alginate solution, without using a higher polymer content, fillers or support structures. 3D porous scaffolds with a height of around 5 mm were printed. Furthermore, the rheological behavior of different pre-crosslinking degrees was studied. Shear forces on cells as well as the flow profile of the bioink inside the printing nozzle during the process were estimated. A high cell viability of printed NIH/3T3 cells embedded in the novel bioink of more than 85% over a time period of two weeks could be observed.